package com.stenio.fancat.service;


import com.sun.org.apache.xerces.internal.impl.dv.util.Base64;
import net.sf.json.JSONObject;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.springframework.stereotype.Service;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLConnection;
import java.security.*;
import java.security.spec.InvalidParameterSpecException;
import java.util.Arrays;

@Service
public class AnalysisEncryptedData {


    /**
     * 获取小程序openID的方法
     * @param appid
     * @param code
     * @param secret
     * @return
     */
    public JSONObject getOpenId(String appid, String code, String secret) {
        BufferedReader in = null;
        //appid和secret是开发者分别是小程序ID和小程序密钥，开发者通过微信公众平台-》设置-》开发设置就可以直接获取，
        String url="https://api.weixin.qq.com/sns/jscode2session?appid="
                +appid+"&secret="+secret+"&js_code="+code+"&grant_type=authorization_code";
        try {
            URL weChatUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection connection = weChatUrl.openConnection();
            // 设置通用的请求属性
            connection.setConnectTimeout(5000);
            connection.setReadTimeout(5000);
            // 建立实际的连接
            connection.connect();
            // 定义 BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            StringBuffer sb = new StringBuffer();
            String line;
            while ((line = in.readLine()) != null) {
                sb.append(line);
            }
            System.out.println(sb.toString());
            return JSONObject.fromObject(sb.toString());
        } catch (Exception e1) {
            throw new RuntimeException(e1);
        }
        // 使用finally块来关闭输入流
        finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }

    }

    /**
     * 解密----->获取手机号
     * @param encryptedData
     * @param sessionKey
     * @param iv
     * @return
     */
    public JSONObject AnalysisEncryptedData(String encryptedData, String sessionKey, String iv) {
        //将前端传过来所有的“+”（实际上已经转换成可“ ”）变成“+”，否则解析的时候报错
        String date = encryptedData.replaceAll(" ","+");
        // 被加密的数据
        byte[] dataByte = Base64.decode(date);
        // 加密秘钥
        byte[] keyByte = Base64.decode(sessionKey);
        // 偏移量
        byte[] ivByte = Base64.decode(iv);

        try {
            // 如果密钥不足16位，那么就补足.  这个if 中的内容很重要
            int base = 16;
            if (keyByte.length % base != 0) {
                int groups = keyByte.length / base + (keyByte.length % base != 0 ? 1 : 0);
                byte[] temp = new byte[groups * base];
                Arrays.fill(temp, (byte) 0);
                System.arraycopy(keyByte, 0, temp, 0, keyByte.length);
                keyByte = temp;
            }
            // 初始化
            Security.addProvider(new BouncyCastleProvider());
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding","BC");
            SecretKeySpec spec = new SecretKeySpec(keyByte, "AES");
            AlgorithmParameters parameters = AlgorithmParameters.getInstance("AES");
            parameters.init(new IvParameterSpec(ivByte));
            cipher.init(Cipher.DECRYPT_MODE, spec, parameters);// 初始化
            byte[] resultByte = cipher.doFinal(dataByte);
            if (null != resultByte && resultByte.length > 0) {
                String result = new String(resultByte, "UTF-8");
                System.out.println(result);
                return JSONObject.fromObject(result);
            }
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        } catch (NoSuchPaddingException e) {
            e.printStackTrace();
        } catch (InvalidParameterSpecException e) {
            e.printStackTrace();
        } catch (IllegalBlockSizeException e) {
            e.printStackTrace();
        } catch (BadPaddingException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (InvalidKeyException e) {
            e.printStackTrace();
        } catch (InvalidAlgorithmParameterException e) {
            e.printStackTrace();
        } catch (NoSuchProviderException e) {
            e.printStackTrace();
        }
        return null;
    }

}
